During storm events, sediments, oils and grease, salts, and metals are washed from parking areas, roads, yards, and fields into drainage ditches or storm drains that discharge into surface streams.
These pollutants can reach concentrations in streams and rivers that can result in health problems from drinking or recreational exposure. Fine sediments flushed into streams can dominate
stream beds blocking the flow of oxygen to developing salmon eggs, clog the gills of rearing juvenile salmon or resident fish, disrupt visual feeding activity, and eliminate the living space for
aquatic insects. Pollutants can be toxic to fish and aquatic insects particularly during early incubation. Toxins can indirectly affect aquatic organisms by binding with oxygen or increasing the susceptibility to other diseases. Pollutants can alter the odor of streams affecting the ability of migrating salmon to locate spawning areas.
The Mat-Su Borough and core areas of Palmer and Wasilla have been the fastest growing regions in Alaska and among the fastest in the nation. As development increases, the concern for stormwater runoff pollution increases. Development within Wasilla is adjacent to Wasilla, Cottonwood, and Little Meadow Creeks. Cottonwood Creek, once a premier rainbow trout fishery, still supports coho salmon, sockeye salmon, and resident rainbow trout. Cottonwood Creek and Wasilla Lake also are important areas for water related recreation.
Beyond the construction phase, development and redevelopment projects change the landscape and can contribute to stormwater pollution well into the future. By planning for onsite stormwater management during design and continuing with ongoing maintenance during operations, developers can be Stormwater Stewards and protect water quality in the community